Pen



FIG. 1 is a right front perspective view of a pen showing my new design;

FIG. 2 is a top plan view;

FIG. 3 is a front elevational view;

FIG. 4 is a right side elevational view; the left side elevational viewis a mirror image;

FIG. 5 is a rear elevational view; and,

FIG. 6 is a bottom plan view thereof.

The ornamental design for a pen, as shown and described.